Changing filters? and Back to Nature

[Xabien]

Hello.
I have the 125 litre Juwel aquarium. TI came with a built in filter which is in the back right vorner of the tank and goes all the way down from top to bottom. I think this spoils the tanks look. If you read my earlier post you would know that I am changing this tank to a cichlid tank soon. Therefore I was thinking of ripping this ugly black filter out of the corner and putting a fluval filter or maybe 2 in in its place. Now my question is this. The fluval that I have at the moment for my second tank (which isn;t running) simply uses a sponge to filter out the dirt. The in built filter in my main tank has a white sponge, carbon, coarse and fine level of filtration and this is supposed to make a bacteria coloney to help the tank. How would a fluval do this?

Also, doesn anybody know if the back to nature backgrounds are good?

Thanks

[Allivymar]

The sponge in the fluval will serve a dual purpose; mechanical filtration as it will catch detritus and biological, as the nitrifying bacteria will colonise it. Chemical filtration (meaning carbon in this case although there are others) is unneccessary unless you are removing meds or tints from the water (like driftwood stain). I *think* fluvals also offer a space for chemical filtration but I might be wrong there.

Heh, and any backround you wish would be considered good; the fish don't really care that much. They might have an issue with mirrors if they're territorial, but they don't know whether its pictures of rocks or aliens in the back of the tank *grin* I've seen folks use colored aluminum foil (on the outside of course, not in the tank).

[Xabien]

ok. Thanks for the information. Any idea what fluval I should use for a 40-50 gallon tank? thinking of getting one